How do you tell if a user is spam or not?

In the middle of the night someone registered a new account and created a new site — all in the same minute. They sure are fast! I don’t know what’s typical about web robots and such, so I thought I would mention this to see what others think.

The username is a woman’s name, but the site is “Absolutely Free Shipping And Delivery [on a product of sorts].

Is this spam? I don’t have a problem with new accounts whatsoever, but I don’t know what’s real or not.